#[cfg(target_os = "linux")]
fn are_you_in_linux() {
    println!("you are running linux");
}

#[cfg(not(target_os = "linux"))]
fn are_you_in_linux() {
    println!("you are *not* running linux");
}


fn main() {
    println!("Hello, world!");
    are_you_in_linux();
    println!("Are you sure?");
    if cfg!(target_os = "linux") {
        println!("Yes. It's definitely linux!");
    } else {
        println!("Yes. It's definitely *not* linux!");
    }
}
